Shopping for speed on eBay.com

Speed was a (derived
after doing a competitive study with the , eBay was able to make
significant improvements to site speed.

…and their Chrome User Experience Report data highlights these improvements, too.

There's still more work ahead but here's eBay's learnings so far.

Web Performance "cuts"

One way to make sites fast is to simply load less code. eBay reduced their text payloads by trimming
all the

Not every pixel on the screen is equally important. The content than something below-the-fold. iOS/Android/desktop and web apps
are aware of this, but what about services? eBay's service architecture has a layer called

Images are for search
results across all platforms, including iOS, Android, and ). eBay has a lot of hand-curated images, which are uploaded
through various tools. Previously the optimizations were up to the uploader, but now eBay enforces
the rules within the tools, so all images uploaded will be optimized appropriately.

The "cut" here is the wasted image bytes sent to users.

Predictive prefetch of static assets , where one page prefetches the static assets required for the next likely page.

With predictive prefetch, when a user navigates to the predicted page, the assets are already in the browser cache. This is done for CSS and JavaScript assets, where the URLs can be retrieved ahead of time. One thing to note here is that it helps only on first-time navigations. On subsequent navigations, the static assets will already be in the cache.

The "cut" here is the network time for CSS and JavaScript static assets on the first navigation.

Prefetching top search results , or stay tuned for a detailed blog
post on the topic from eBay's engineers.

The "cut" here can either be server processing time or network time,
depending on where the item is cached.

Eager downloading of search images

When users type in letters in the search box, suggestions pop-up. These suggestions do not change for letter combinations for at least a day. They are ideal candidates to be cached and served from a

For the web platform, the homepage content for unrecognized users is the same for a particular region. These are users who are either using eBay for the first time or starting a fresh session, hence no personalization. Though the homepage creatives keep changing frequently there is still room for caching.

eBay decided to cache the unrecognized user content (HTML) on their edge network (

iOS/Android app parsing improvements

This applies to

All the performance "cuts" eBay made collectively contributed towards moving the needle, and it happened over a period of time. The releases were phased in throughout the year, with each release shaving off tens of milliseconds, ultimately reaching the point where eBay is now: